Visible light is a form of electromagnetic radiation, with electric and magnetic vectors oscillating perpendicular to the direction of propagation, and generally in any direction perpendicular to the direction of propagation. Polarization of the light restricts the oscillations into only a few directions. Polarizers, such as polarizing filters, absorb or block incident light oscillating in all but one plane, yielding planar polarization. Polarization of a light source therefore also reduces the intensity of the source theoretically by 50%, but in practice closer to 60-65%.
Liquid crystal displays (LCDs), the predominant technology currently used in most displays, rely on polarized light. Liquid crystal displays work by sandwiching a layer of liquid crystal molecules between two transparent electrodes and two polarizing filters. A combination of a backlight and control of the voltage applied to each pixel of the display allows light to escape and create images we see as the viewer. The use of the polarizing filters therefore results in an increased thickness of the display, as well as a reduction in the intensity of the light which emerges from the display.
Therefore, there remains a need for providing polarized light with the use of fewer components while also increasing the intensity of the light.